On Tue, 15 May 2018 13:13:15 +0100, Martin Brown
wrote:

On 15/05/2018 13:01, Clive Arthur wrote:
On 15/05/2018 11:58, Martin Brown wrote:
On 15/05/2018 11:17, Dave Plowman (News) wrote:

snipped

Despite being rated at 13 amps, most sockets and plugs aren't happy to
carry that for very long periods. They are a domestic connector and
really
for intermittent use at full capacity. As with a kettle or washing
machine
etc. Hence things like 13 amp water heaters normally not plugged in, but
hard wired. Same sort of thing with storage rads.

Indeed. 3kW is pushing it on a standard plug and socket for a near
continuous load. They are fine for intermittent loads like kettles.

ISTR there is a revision that recommends no portable appliances with
load 2.4kW due to the fragile nature of nominally 13A plug and sockets.

I can't see anything official (and I didn't try that hard) but a
supporting data point is fan heaters.* Usually 2kW max, sometimes a
little more, but I've not seen 3kW.

I don't know where it is in what legislation but it came up in
conversation with a sparks doing some alterations at out VH.

I have a 3kW fan heater and it has cooked a plug and socket not quite to
the point of failure but more than I was comfortable with one cold day.
Enough to significantly discolour and distort the plastic casings.

You know that "cheapest first" option you get in the listings on
Ebay.................................. :-)



I play at PAT testing from time to time, I always strip and examine
the failiures, a lot of the cheaper multiway sockets fail due to
discolouration. The conductors are not exactly very generous on size
or contact area.

For a 3kW heater, I would go MK or a similar known brand.

AB